1. Field of the Invention
The invention relates to equipment for measuring parameters of production processes, and more particularly, it deals with methods for measuring parameters of the solid phase of slurries and an apparatus for carrying out the method.
2. Description of the Prior Art
Known in the art are various methods for measuring parameters of the solid phase of slurries.
Thus a method and apparatus are widely used for measuring particle size of the solid phase in slurries (cf. Kn. Khan J.A. "Oprobovanie i kontrol teknnologicheskikh processov obogascheniya", M., "Nedra", 1979, pp. 119-120) which are based on determining the position of a micrometric feeler, which reciprocates in the flow of the slurry under study, at the moment it is stopped owing to a solid phase particle being retained between the surfaces of the micrometric feeler and a trough along which the slurry is supplied.
The prior art method and apparatus are deficient due to rapid wear, hence, low reliability of the micrometric feeler which is permanently in contact with abrasive particles of the slurry under study. This results in a scatter of results in measuring the solid phase particles in slurries having the same particle size, i.e. in a low accuracy of measurements.
Also known in the art are a method and apparatus for measuring particle size of the solid phase of slurries (cf., for example, razvertyvauschii fotosediment graf "Analizette 20", prospect firmy FRITSCH". D-6580, IDAR-Obershtain -I (GFR) based on the measurement of the time of setting of solid phase particles of a slurry in a vessel containing water.
However, the abovementioned method requires preliminary sampling of the slurry under study from the production flow, extraction of the solid phase from the slurry sample, weighing and delivery to the place of measurement. This results in long measurement times (about 20 to 40 minutes) thus greatly restricting the field of application.
Known in the art is a method for measuring parameters of solid phase of slurries (cf., for example Armco Grinding Systems, "Take Control of four Grinding Circuil) based on directing radiation into the fluid under study. Ultrasonic; oscillations at two fixed frequencies are used,, measuring the amplitude of ultrasonic oscillations that pass through the fluid under study and assessing the concentration of the solid phase and the concentration of the critical particle size fraction of the solid phase in the slurry under study by the value of this amplitude, the slurry under study being degassed before directing ultrasonic oscillations thereinto in a special tank by combined action of vacuum and centrifugal forces generated by an impeller.
Known in the art is an apparatus for carrying out the method for measuring parameters of the solid phase of slurries (cf., for example, ibid.,) comprising two measurement channels, each consisting of a series circuit including a pulse generator, a power amplifier an emitting ultrasonic transducer, a receiving ultrasonic transducer, a received pulse amplifier, and an electronic switch. The apparatus also comprises a one-shot multivibrator connected between the pulse generator and electronic switch and also a switching circuit connected between the pulse generators of the two channels, a multivibrator having an output connected to the input of the switching circuit, a comparator, a setting means, a study function selector, a recorder, and also a mechanical gas bubble separator consisting of a tank for air removal and an impeller having a drive motor. The emitting and receiving transducers of one of the measurement channels are secured directly to the walls of a vessel containing a fluid under study.
It should be noted, however, that since it is necessary in the abovedescribed method and apparatus to effect the preliminary removal of gaseous phase from the fluid under study, hence, to have a mechanical gas bubble separator in the form of an apparatus including a rotary impeller, reliability of the process of measurement of parameters of the solid phase in slurries is rather low.
Under the action of abrasive particles in the slurry under study, intensive wear of rotating parts of the mechanical gas bubble separator occurs which results in variations of its characteristics, hence, in changes in quality of degassing during operation. To maintain quality of degassing at the desired level, regular stoppage of the apparatus for measuring parameters of the solid phase of slurries is necessary for maintenance and replacement of worn mechanical components. The drive motor of the impeller consumes much energy which results in added cost bearing in mind continuous operation of the measuring apparatus. Therefore, the use of the mechanical gas bubble separator lowers reliability, impairs accuracy of measurements and results in an increased cost of both the apparatus for measurement as a whole and operation.